Data providers, such as Bloomberg and Reuters-Thomson, aggregate data related to a particular industry from different sources and offer access to a subset of the data via a subscription. For example, the aggregated data may include financial market data, legal data, health care data, technology data, science data, and government data. To illustrate, a subscription to financial market data may include streaming real-time quotes for all securities listed on the New York Stock Exchange (NYSE). For financial market data, access to the data may be provided using a specialized computer terminal, such as a Bloomberg terminal or a Reuters terminal, to enable access to a subset of the financial market data via the subscription. When a financial trader attempts to access the financial market data, the terminal may determine whether the financial trader has a subscription that enables the financial trader to access the financial market data and then allows or denies access to the financial market data accordingly.
The subscription information is typically managed by the data provider. One way the terminal can determine whether the financial trader has a subscription to access a portion of the financial market data is for the terminal to send a request to the data provider asking whether the financial trader has a subscription to access the financial market data and then allow or deny access to the financial market data accordingly. However, the exchange of messages between the terminal and the data provider may result in a delay before the financial trader is allowed to access the requested financial market data. In addition, the work load for the data provider increases because the data provider is repeatedly checking whether each financial trader can access a particular portion of the financial market data.
Another way to determine whether the financial trader has a subscription to access a portion of the financial data is to create a local copy of the master authorization database at each terminal. However, copying a large master authorization database to many terminals takes time and results in the master authorization database occupying a large portion of memory at the terminal. In addition, each time a trader changes his or her subscription, or the data provider offers new or updated packaged financial-products, the trader cannot access the financial market data associated with the new subscription until the master authorization database with the new subscription information is copied to the trader's terminal.